Make UISearchController search bar automatically a

问题:

I've implemented a UISearchController with its search bar in a navigatiom bar and I would like to make the search bar active when the view is loaded. When I say active, I mean that the keyboard appears and the user can type his/her search without tap the search bar.

I initialised the UISearchController with the following code:

- (void)viewDidLoad
{
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    [self.searchController setSearchResultsUpdater:self];
    [self.searchController setDimsBackgroundDuringPresentation:NO];
    [self.searchController setHidesNavigationBarDuringPresentation:NO];
    [self.navigationItem setTitleView:self.searchController.searchBar];

    [self setDefinesPresentationContext:YES];

    [self.searchController.searchBar setDelegate:self];
    [self.searchController.searchBar setShowsCancelButton:YES];
    [self.searchController.searchBar setPlaceholder:@"City or Airfield"];

    [self.searchController.searchBar sizeToFit];
}

I've tried to make my search controller active, call [self.searchController.searchBar becomeFirstResponder] and directly call searchBarSearchButtonClicked but nothing works.

回答1:

Try calling

[self.searchController setActive:YES]

before

[self.searchController.searchBar becomeFirstResponder]

If the above is not working, try something like this:

- (void)viewDidLoad {
    [super viewDidLoad];
    ...
    [self initializeSearchController];
    ....
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [self.searchController setActive:YES];
    [self.searchController.searchBar becomeFirstResponder];
}

- (void)initializeSearchController {
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    self.searchController.searchResultsUpdater = self;
    self.searchController.dimsBackgroundDuringPresentation = NO;
    self.searchController.delegate = self;
    self.searchController.searchBar.delegate = self;
    [self.searchController.searchBar sizeToFit];

    [self.tableView setTableHeaderView:self.searchController.searchBar];
    self.definesPresentationContext = YES;
}

回答2:

To activate the search bar:

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [self.searchController setActive:YES];
}

"becomeFistResponder" can be called to make the keyboard appear only when UISearchController is loaded .

- (void)didPresentSearchController:(UISearchController *)searchController
{
    [searchController.searchBar becomeFirstResponder];
}

回答3:

Besides doing what the other users suggested, I also did the following, and it worked:

searchController.definesPresentationContext = YES;